Fuze apparatus



Allg. 22, 1967 W, R. PETERSON ET Al. 3,336,869

FUZE APPARATUS Filed May 5, 1966 JAMES F. K 0 WALICK Unted States Patent C "ce 3,336,869

3,336,869 FUZE APPARATUS William R. Peterson, Levittown, and James F. Kowalick, Southampton, Pa., assignors to the United States of America as represented by the Secretary of the Army Filed May 5, 1966, Ser. No. 548,370 6 Claims. (Cl. 102-27) ABSTRACT OF THE DISCLOSURE As an abstract of the disclosure, the invention is directed to a mild detonating fuze arrangement in which each of a pair of lengths of high explosive core has an end portion longitudinally aligned adjacent but spaced from each other. Delay connecting means are provided in the form of a helically wound insulated metallic fuze wire embodied in a tubular member and having bare fuze wire ends connected to the core. The wire is preferably of aluminum and is covered by a plating of palladium-ruthemum alloy to provide a mild detonating fuze train'with a long interval delay.

This invention relates to a fuze apparatus and, more particularly, to a train of detonating cord.

In the detonating fuze method of detonating explosives,

the need has arisen for obtaining a long interval delay at a predetermined time after an initial ignition of the fuze.

-It is one of the objects of the invention to provide a mild detonating fuze train having a long interval delay connection.

Another object is to provide such a delay connection in a fuze that is capable of operation after a required exposure to an extremely high temperature.

A further object of the invention is to provide a reliable and accurate delay connection fuze apparatus which can be conveniently attached to two ends of a detonating fuze without regard to the direction of propagation in the detonation wave.

These and other objects, features and advantages will become apparent from the following description and accompanying drawings in which:

FIG. 1- is a plan View of a detonating cord embodying thexllincples of the invention is a sectional view taken substa t' line 2 2 of FIG. 1. n muy along The mild detonating fuze 10, having a high explosive core 11 preferably of pentaerythritol tetranitrate contained within a Waterproof sheath overlaid with reinforced coverings, has a very high velocity of detonation, approximately 21,000 feet per second. Its explosive force 1s such that it may be used to detonate high explosives adjacent to it.

In accordance with the present invention, a long interval delay device, shown generally at 12 (FIG. 1), is connectively inserted between two lengths of mild detonating fuze, each length being inserted and crimped in a corresponding externally threaded retainer 13 which contains a high explosive charge containing an igniter composition capable of the reducing detonation to deflagration and igniting a fuze wire 14 of the interconnecting delay device 12.

Each explosive charge contains a primary explosive 15 such as lead azide in abutment with the corresponding Patented lAug. 22, 1967 end portions of the MDF cores 11 and the detonation reducing igniter material preferably includes a Zr/Pb02 composition 16 intermediate the primary explosive 15 and Mg/Sr02 composition 17, the latter being adjacent and capable of igniting at a high temperature the corresponding bare end of insulated bimetallic component fuze wire 14 which is of aluminum material covered by a plating of palladium ruthenium alloy. The fuze wire is insulated from adjacent material with an overbraiding 20 of liberglass or Teflon, or a combination of both. The long interval delay element fuze wire is of predetermined length and formed with a plurality of helical turns 'or windings and is embodied in a tubular cover 18 whose end portions are appropriately secured to a suitably apertured closure body 19 that receives and retains the corresponding end portion of the delay connector fuze wire 14. Each body member 19 has its outer end formed with an enlarged threaded opening to securely receive the threaded portion of the corresponding retainer 13. The retainer, body and cover constructions are preferably of an aluminum alloy.

The selected end of fuze wire 14 ignites at the melting point of aluminum (660 C.) and continues to burn in an exothermic reaction at a rapid uniform rate, approximately one foot per second until it ignites the other high explosive (in going from deagration to detonation) and its MDF core.

The delay device can provide a long interval in excess of 5 seconds while being very small in size and light in weight, and is particularly applicable to aerospace vehicles having a very high temperature requirement.

Various modications, alterations or changes may be restorted to without departing from the scope of the invention as dened in the appended claims.

We claim:

1. In a mild detonating fuze having a plurality of lengths of a high explosive core, said lengths each having an end portion longitudinally aligned adjacent but spaced from each other, delay connecting means comprising a helically wound insulated metallic fuze wire of predetermined length embodied in a tubular member and having bare fuze Wire ends connected to respective ones of said end portions, said wire being covered by a plating of palladinm-ruthenium alloy, so constructed and arranged to provide a mild detonating fuze train With a long interval delay.

2. The structure of claim 1 wherein said fuze wire is of aluminium and is covered by a plating of palladiumruthenium alloy.

3. The structure of claim 2 in which a primary explosive abuts each of said end portions and an igniter composition respectively interconnects each primary explosive with a corresponding one of said fuze wire ends, so constructed and arranged that either of said igniter compositions is capable of reducing detonation to deflagrat-ion.

4. The structure of claim 1 in which a primary explosive abuts each of said end portions and an igniter composition respectively interconnects each primary explosive with a corresponding one of said fuze wire ends, so constructed and arranged that either of said igniter compositions is capable of reducing detonation to deflagration.

5. In a mild detonating fuze having a plurality of lengths of a high explosive core, said lengths each having an end portion longitudinally aligned adjacent but spaced from each other, delay means comprising an in- References Cited UNITED STATES PATENTS Easton 102--70 4Eisler et al. 102-21.6 Lang 102--20 Silverman 102-20 BENJAMIN A. BORCHELT, Primary Examiner.

10 V. R. PENDEGRASS, Assistant Examiner. 

1. IN A MILD DETONATING FUZE HAVING A PLURALITY OF LENGTHS OF A HIGH EXPLOSIVE CORE, SAID LENGTHS EACH HAVING AN END PORTION LONGITUDINALLY ALIGNED ADJACENT BUT SPACED FROM EACH OTHER, DELAY CONNECTING MEANS COMPRISING A HELICALLY WOUND INSULATED MATALLIC FUZE WIRE OF PREDETERMINED LENGTH EMBODIED IN A TUBULAR MEMBER AND HAVING BARE FUZE WIRE ENDS CONNECTED TO RESPECTIVE ONES OF SAID END PORTIONS, SAID WIRE BEING COVERED BY A PLATING OF PALLADIUM-RUTHENIUM ALLOY, SO CONSTRUCTED AND ARRANGED TO PROVIDE A MILD DETONATING FUZE TRAIN WITH A LONG INTERVAL DELAY. 